This invention relates to apparatus for concomitantly cleaning toner particles from and removing remaining electrostatic charge from the imaging surface of an electrophotographic copier following image transfer to a copy sheet.
In image-transfer, or plain paper, electrophotographic copiers, it is common to provide an AC discharge corona, quench lamp or similar device between the transfer station and charge corona to remove the latent electrostatic image remaining on the imaging surface after transfer of the developed image. Not only does such charge removal assist in the subsequent removal of toner particles from the imaging surface, but if left on the imaging surface, the original image may be superimposed on an electrostatic latent image formed later on the same imaging surface portion. Satomi U.S. Pat. No. 4,095,980 shows one such copier in which a discharge corona placed before the cleaning unit and a quench lamp placed after the cleaning unit are used to dissipate remaining electrostatic charge from the imaging drum.
While it is thus desirable to incorporate imaging surface discharge devices in an electrophotographic copier, such devices also have their drawbacks. Not only do these devices take up added space along the drum periphery, but they often draw an appreciable amount of power and thus generate heat which must be dissipated.